A communication method and apparatus

Abstract

The application provides a communication method and device. The communication method comprises: a network device sends downlink control information to a terminal device, the downlink control information comprises indexes of N pre-coding matrix subsets; the terminal device determines at least N pre-coding matrices from the N pre-coding matrix subsets according to the downlink control information, and sends uplink signals based on the at least N pre-coding matrices, which improves transmission performance, reduces signaling overhead of sub-band pre-coding indication information and complexity of detecting the sub-band pre-coding indication information of the terminal device.

Description

Technical Field

[0001] The present application relates to the field of wireless communications, and in particular to a communication method and device. Background Art

[0002] During uplink transmission, when both the terminal and the base station are equipped with multiple antennas, the base station sends precoding information to the terminal via downlink control information (DCI). The terminal then obtains a precoding matrix based on this information and uses it to map the data to be transmitted to multiple antenna ports, sending it over the physical uplink shared channel (PUSCH). Precoding makes the transmitted signal more directional, rather than simply radiating in all directions.

[0003] The physical uplink shared channel supports codebook-based transmission mode and non-codebook-based transmission mode. For the codebook-based transmission mode, the base station selects a precoding matrix in the codebook and sends a transmitted precoding matrix indicator (TPMI) to the terminal. The TPMI corresponds to a precoding matrix. The accuracy of the precoding matrix will affect the demodulation performance of the PUSCH. The NR system only supports uplink broadband precoding, that is, the same precoding matrix is ​​used on the scheduled bandwidth. When the frequency selection characteristics of the channel are relatively large, this method will cause system performance loss. If subband precoding is used, the base station sends information to the terminal device to indicate the TPMI of each subband, and the signaling overhead will increase. Therefore, when designing uplink precoding, reducing signaling overhead and improving transmission performance become contradictory aspects. Summary of the Invention

[0004] The present invention provides a communication method and device for reducing the signaling overhead of sub-band precoding.

[0005] In a first aspect, the present application provides a communication method, which may be performed by a terminal device or a chip used in the terminal device. The following description is made using the terminal device as an example. The terminal device receives downlink control information sent by a network device, where the downlink control information includes indexes of N precoding matrix subsets, where the N precoding matrix subsets are one or more of the multiple precoding matrix subsets divided by the first codebook, and where at least one precoding matrix subset includes at least two precoding matrices in the N precoding matrix subsets. The terminal device determines at least N precoding matrices from the N precoding matrix subsets, and the terminal device sends an uplink signal based on the determined at least N precoding matrices, where N is a positive integer.

[0006] In the above embodiment, the terminal device can select one or more precoding matrices from N precoding matrix subsets for transmitting uplink signals, thereby improving transmission performance. Furthermore, the terminal device receives information indicating the index of the precoding matrix subset via downlink control information. Since the number of precoding matrix subsets divided by the first codebook can be less than or much less than the number of precoding matrices contained in the first codebook, receiving information indicating the index of the precoding matrix subset can reduce the overhead of downlink control information compared to receiving information indicating the index of the precoding matrix contained in the entire first codebook, thereby reducing the complexity of terminal device detection and the power consumption of the terminal device.

[0007] In an optional embodiment, the downlink control information also includes resource indication information for indicating a first downlink reference signal, and the terminal device determines at least N precoding matrices in N precoding matrix subsets based on the first downlink reference signal on the resources indicated by the resource indication information.

[0008] In the above embodiment, the terminal device determines at least N precoding matrices based on the first downlink reference signal. Since the first downlink reference signal can reflect the channel state of the downlink channel, the terminal device can consider the influence of the channel state and determine the appropriate precoding matrix to obtain better multi-antenna gain.

[0009] In one optional embodiment, the uplink signal is a physical uplink shared channel (PUSCH), which occupies M subbands. The downlink control information also includes indication information of the M subbands. The at least N precoding matrices are M precoding matrices, and each of the M subbands corresponds to one of the M precoding matrices, where M is a positive integer greater than N. In this case, the precoding matrices corresponding to at least two of the M subbands belong to the same precoding matrix subset. The terminal device transmits the PUSCH on the M subbands based on the M precoding matrices.

[0010] In an optional implementation, the uplink signal is a physical uplink shared channel PUSCH, which occupies N subbands, that is, M is equal to N. The downlink control information also includes indication information of the N subbands. The N precoding matrix subsets correspond one-to-one to the N subbands. The terminal device sends PUSCH on the N subbands based on the N precoding matrices.

[0011] In an optional implementation, the uplink signal is a physical uplink shared channel (PUSCH), and the PUSCH occupies M subbands, where M is greater than N. The downlink control information also includes indication information of the M subbands, and the N precoding matrix subsets constitute one precoding matrix subset, where N is 1. A precoding matrix for each of the M subbands is determined based on one precoding matrix subset, and at least N precoding matrices constitute M precoding matrices. The M subbands and the M precoding matrices have a one-to-one correspondence, and the terminal device sends the PUSCH on the M subbands based on the M precoding matrices.

[0012] In the above method, the downlink control information indicates the index of the precoding matrix subset and the subband indication information. Each subband corresponds to a precoding matrix, which can be, for example, the precoding matrix most suitable for the terminal device to send uplink signals, which is beneficial to improving transmission performance.

[0013] It should be noted that the M precoding matrices may be completely different precoding matrices, or may be partially identical precoding matrices, which is not limited in the embodiment of the present invention.

[0014] In an optional embodiment, at least two different precoding matrix subsets in the multiple precoding matrix subsets correspond to different values ​​of the first codebook parameter, and the first codebook parameter includes a phase. In an optional manner, the multiple precoding matrix subsets are K, the first codebook contains L precoding matrices, and the index of the precoding matrix included in each precoding matrix subset in the K precoding matrix subsets satisfies The values ​​of are the same; or, the indexes of the precoding matrices contained in each precoding matrix subset satisfy the same value of mod(j,K). Wherein, j is the index of the precoding matrix in the first codebook, is the floor function, is the ceiling function.

[0015] In an optional manner, the first codebook is generated based on a discrete Fourier transform matrix, and at least two different precoding matrix subsets among the multiple precoding matrix subsets correspond to different column vectors in the discrete Fourier transform matrix.

[0016] In an optional manner, the downlink control information further includes an index of at least one precoding matrix, where the at least one precoding matrix is ​​a precoding matrix that the terminal device is not expected to use, or a precoding matrix that the terminal device is expected to avoid using. In an optional manner, the precoding matrix that the terminal device is not expected to use is a precoding matrix of an interfering channel.

[0017] In the above manner, when the terminal device determines at least N precoding matrices from the N precoding matrix subsets, it also considers the precoding matrices that the network device does not expect the terminal device to use, so that the terminal device can minimize interference and improve transmission performance.

[0018] In a second aspect, the present application provides a communication method, which may be performed by a network device or a chip used in the network device. The following description takes the network device as an example. The network device determines N precoding matrix subsets, and the network device sends downlink control information to a terminal device. The downlink control information includes indexes of the N precoding matrix subsets, where the N precoding matrix subsets are one or more of the multiple precoding matrix subsets divided by the first codebook. Among the N precoding matrix subsets, there is at least one precoding matrix subset that includes at least two precoding matrices.

[0019] In the above manner, the network device indicates the index of one or more precoding matrix subsets through downlink control information. Since the number of precoding matrix subsets divided by the first codebook can be less than or much less than the number of precoding matrices included in the first codebook, compared to indicating the index of the precoding matrix included in the first codebook through downlink control information, the network device indicates the index of the precoding matrix subset through downlink control information, which can reduce the signaling overhead of the downlink control information.

[0020] In an optional embodiment, the downlink control information also includes resource indication information for indicating a first downlink reference signal, and the terminal device determines at least N precoding matrices in N precoding matrix subsets based on the first downlink reference signal on the resources indicated by the resource indication information.

[0021] In an optional implementation, at least N precoding matrices correspond to M subbands, M is greater than or equal to N, and the network device receives uplink signals on the M subbands.

[0022] In an optional implementation, the number of the at least N precoding matrices is M, the M precoding matrices correspond to the M subbands in a one-to-one manner, and the network device receives uplink signals on the M subbands.

[0023] It should be noted that the M precoding matrices may be completely different precoding matrices, or may be partially identical precoding matrices, which is not limited in the embodiment of the present invention.

[0024] In an optional implementation, the uplink signal is a physical uplink shared channel PUSCH.

[0025] In an optional implementation, N precoding matrix subsets constitute one precoding matrix subset, N is 1, and at least N+1 precoding matrices belong to the same precoding matrix subset.

[0026] In an optional implementation, at least two different precoding matrix subsets among the multiple precoding matrix subsets correspond to different values ​​of a first codebook parameter, and the first codebook parameter includes a phase.

[0027] In an optional implementation, the number of precoding matrix subsets is K, the first codebook includes L precoding matrices, and the index of the precoding matrix included in each precoding matrix subset of the K precoding matrix subsets satisfies: The values ​​of are the same; or, the indexes of the precoding matrices contained in each precoding matrix subset satisfy the same value of mod(j,K). Wherein, j is the index of each precoding matrix in the first codebook, is the floor function, is the ceiling function.

[0028] In an optional manner, the first codebook is generated based on a discrete Fourier transform matrix, and at least two different precoding matrix subsets among the multiple precoding matrix subsets correspond to different column vectors in the discrete Fourier transform matrix.

[0029] In an optional manner, the downlink control information further includes an index of at least one precoding matrix, and the at least one precoding matrix is ​​a precoding matrix that the terminal device is not expected to use, or a precoding matrix that the terminal device is expected to avoid using.

[0030] In an optional manner, the precoding matrix used by the terminal device is not expected to be the precoding matrix of the interference channel.

[0031] In the above manner, the network device indicates the indexes of the N precoding matrix subsets while also indicating the precoding matrices that the network device does not expect the terminal device to use, which is beneficial for the terminal device to minimize interference and improve transmission performance.

[0032] According to a third aspect, a communication device is provided, wherein the communication device has the function of implementing the behavior in the method example of the first aspect. The function can be implemented by hardware, or can be implemented by hardware executing corresponding software. The hardware or software includes one or more modules corresponding to the above functions. In one possible design, the communication device includes: a receiving unit, the transceiver unit is used to receive downlink control information, the downlink control information includes indexes of N precoding matrix subsets, the N precoding matrix subsets are one or more of the multiple precoding matrix subsets divided by the first codebook, and among the N precoding matrix subsets, there is at least one precoding matrix subset including at least two precoding matrices. A processing unit is used to determine at least N precoding matrices in the N precoding matrix subsets. A sending unit is used to send an uplink signal based on at least N precoding matrices, where N is a positive integer.

[0033] These modules can perform the corresponding functions in the above-mentioned first aspect method example. For details, please refer to the detailed description in the method example, which will not be repeated here. At the same time, regarding the technical effects brought about by the third aspect or the corresponding implementation method, please refer to the introduction of the technical effects of the first aspect or the corresponding implementation method.

[0034] In a fourth aspect, a communication device is provided, wherein the communication device has the function of implementing the behavior in the method example of the second aspect. The function can be implemented by hardware, or can be implemented by hardware executing corresponding software. The hardware or software includes one or more modules corresponding to the above functions. In one possible design, the communication device includes: a processing unit, which is used to determine N precoding matrix subsets. A sending unit is used to send downlink control information, and the downlink control information includes indexes of N precoding matrix subsets, and the N precoding matrix subsets are one or more of the multiple precoding matrix subsets divided by the first codebook. Among the N precoding matrix subsets, there is at least one precoding matrix subset including at least two precoding matrices.

[0035] These modules can perform the corresponding functions in the above-mentioned second aspect method example. For details, please refer to the detailed description in the method example, which will not be repeated here. At the same time, regarding the technical effects brought about by the third aspect or the corresponding implementation method, please refer to the introduction of the technical effects of the first aspect or the corresponding implementation method.

[0036] In a fifth aspect, a communication device is provided. The communication device may be the terminal device in the above-described method embodiment, or a chip provided in the terminal device, or a larger device including the terminal device. The communication device includes at least one processor and an interface circuit, and optionally, a memory. The interface circuit is configured to provide input or output of instructions and / or data to the at least one processor, and the memory is configured to store computer programs or instructions. At least the processor is coupled to the memory and the interface circuit. When the at least one processor executes the computer program or instructions, the communication device executes the method performed by the terminal device in the above-described method embodiment.

[0037] In a sixth aspect, a communication device is provided. The communication device may be a network device in the above-described method embodiment, or a chip disposed in the network device, or a larger device including the network device. The communication device includes at least one processor and an interface circuit, and optionally, a memory. The interface circuit is configured to provide input or output of instructions and / or data to the at least one processor, and the memory is configured to store computer programs or instructions. At least the processor is coupled to the memory and the interface circuit. When the at least one processor executes the computer program or instructions, the communication device executes the method performed by the network device in the above-described method embodiment.

[0038] In a seventh aspect, a computer program product is provided, comprising: a computer program code, which, when run, enables the method performed by the terminal device in the above aspects to be executed.

[0039] In an eighth aspect, a computer program product is provided, comprising: a computer program code, wherein when the computer program code is run, the method performed by the network device in the above aspects is executed.

[0040] In a ninth aspect, the present application provides a chip system comprising a processor for implementing the functions of the terminal device in the methods of the above aspects. In one possible design, the chip system further comprises a memory for storing program instructions and / or data. The chip system may be composed of a chip alone or may include a chip and other discrete components.

[0041] In a tenth aspect, the present application provides a chip system comprising a processor for implementing the functions of the network device in the methods of the above aspects. In one possible design, the chip system further comprises a memory for storing program instructions and / or data. The chip system may be composed of a chip alone or may include a chip and other discrete components.

[0042] In an eleventh aspect, the present application provides a computer-readable storage medium storing a computer program, which, when executed, implements the methods executed by a terminal device in the above aspects.

[0043] In a twelfth aspect, the present application provides a computer-readable storage medium, which stores a computer program. When the computer program is executed, it implements the methods performed by the network device in the above aspects.

[0044] In a thirteenth aspect, a communication system is provided, which includes the network device and terminal device involved in any of the above aspects. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 A possible communication architecture diagram provided for this application;

[0046] Figure 2 A flow chart of the communication method provided in this application;

[0047] Figure 3 Schematic diagram of the hardware structure of the network equipment and terminal equipment provided for this application;

[0048] Figure 4 A schematic diagram of a possible device provided for this application;

[0049] Figure 5 A schematic diagram of a possible device provided for this application;

[0050] Figure 6A schematic diagram of the structure of a possible communication device provided by this application; DETAILED DESCRIPTION

[0051] The technical solutions in the embodiments of the present application can be applied to various communication systems, such as long term evolution (LTE) systems, fifth generation (5G) mobile communication systems, and future mobile communication systems.

[0052] like Figure 1 As shown, a schematic diagram of a possible network architecture applicable to an embodiment of the present application includes a terminal device 110 and an access network device 120, and optionally a core network device 130. The terminal device 110 and the access network device 120 can communicate via the Uu air interface, which can be understood as a universal UE-to-network interface between the terminal device 110 and the access network device 120. Transmission over the Uu air interface includes uplink transmission and downlink transmission.

[0053] For example, uplink transmission refers to the terminal device 110 sending an uplink signal to the access network device 120. The uplink signal may include one or more of uplink data, uplink control information, or a reference signal (RS). The channel used to transmit the uplink signal is called an uplink channel, and the uplink channel may be a PUSCH or a physical uplink control channel (PUCCH). PUSCH is used to carry uplink data, and uplink data may also be called uplink data information. PUSCH may also be used to carry uplink control information. PUCCH is used to carry uplink control information (UCI) fed back by the terminal device. UCI may include one or more of channel state information (CSI), acknowledgement (ACK), negative acknowledgement (NACK), or scheduling request (SR).

[0054] Taking the fifth generation (5G) communication system as an example, the core network device 130 includes: access and mobility management function (AMF), session management function (SMF), or user plane function (UPF), etc. The access network device 120 is a device with wireless transceiver functions, used to communicate with the terminal device 110. The access network device includes but is not limited to base stations (BTS, Node B, eNodeB / eNB, or gNodeB / gNB), transmission reception points (TRPs), 3GPP later evolved base stations, access nodes in WiFi systems, wireless relay nodes, wireless backhaul nodes, etc. The base station can be: a macro base station, a micro base station, a pico base station, a small base station, a relay station, etc. Multiple base stations can support networks with the same access technology mentioned above, or they can support networks with different access technologies mentioned above. The base station can include one or more co-located or non-co-located transmission and reception points. In the following embodiments, the access network devices and core network devices are collectively referred to as network devices relative to the terminal devices.

[0055] Some nouns or terms used in this application are explained below, and these nouns or terms are also considered part of the invention content.

[0056] 1. Terminal Equipment

[0057] The terminal device can be simply referred to as a terminal, also known as user equipment (UE), which is a device with wireless transceiver capabilities. The terminal device can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; it can also be deployed on the water (such as a ship, etc.); it can also be deployed in the air (for example, on an airplane, a drone, a balloon, and a satellite, etc.). The terminal device can be a mobile phone, a car, a tablet computer, a smart speaker, a detector, a gas station sensor, a computer with wireless transceiver capabilities, a virtual reality terminal device, an augmented reality terminal device, a wireless terminal device in industrial control, a wireless terminal device in unmanned driving, a wireless terminal device in telemedicine, a wireless terminal device in a smart grid, a wireless terminal device in transportation safety, a wireless terminal device in a smart city, or a wireless terminal device in a smart home, etc. The terminal device can also be fixed or mobile. The embodiments of the present application are not limited to this.

[0058] In the embodiments of the present application, the apparatus for implementing the functions of the terminal may be a terminal device; or it may be an apparatus capable of supporting the terminal device in implementing the functions, such as a chip system, which may be installed in the terminal device. In the embodiments of the present application, the chip system may be composed of a chip, or may include a chip and other discrete devices. In the technical solutions provided in the embodiments of the present application, the technical solutions provided in the embodiments of the present application are described by taking the terminal device as an example of the apparatus for implementing the functions of the terminal device.

[0059] 2. Network Equipment

[0060] The network device may be an access network device, which may also be referred to as a radio access network (RAN) device or a base station. It is a device that provides wireless communication functions for terminal devices. Access network devices include, for example, but are not limited to: next-generation node B (gNB) in 5G, evolved node B (eNB), baseband unit (BBU), transmitting and receiving point (TRP), transmitting point (TP), access network devices in future mobile communication systems, or access points in WiFi systems. The access network device may also be a wireless controller, a centralized unit (CU), and / or a distributed unit (DU) in a cloud radio access network (CRAN) scenario, or the network device may be a relay station, an on-board device, or a network device in a future evolved PLMN network.

[0061] The terminal device can communicate with multiple access network devices of different technologies. For example, the terminal device can communicate with an access network device that supports long term evolution (LTE), can also communicate with an access network device that supports 5G, and can also communicate with an access network device that supports LTE and an access network device that supports 5G at the same time. The embodiments of the present application are not limited.

[0062] In the embodiments of the present application, the apparatus for implementing the function of a network device may be a network device; or it may be a device capable of supporting the network device in implementing the function, such as a chip system, which may be installed in the network device. In the technical solutions provided in the embodiments of the present application, the technical solutions provided in the embodiments of the present application are described using the network device as an example.

[0063] 3. Uplink (UL) communication and downlink (DL) communication

[0064] In wireless communication systems, communications can be categorized into different types based on the types of transmitting and receiving nodes. Information sent from a network device to a terminal device is typically referred to as downlink (DL) communication, while information sent from a terminal device to a network device is referred to as uplink (UL) communication. In fourth-generation (4G) and 5G wireless communication systems—new radio access technology (NR) systems—uplink communications can obtain channel state information (CSI) measurements using a sounding reference signal (SRS), while downlink communications can obtain channel state information using a channel state information reference signal (CSI-RS).

[0065] 4. Time-Frequency Resource Granularity

[0066] Time-frequency resources can also be simply referred to as resources, and time-frequency resource granularity can also be simply referred to as resource granularity. In the NR system, the resource granularity of uplink scheduling supports two types, or in other words, there are two types of time-frequency resource allocation in NR, namely the allocation type based on resource group (resource block group, RBG) (also known as resource allocation 0, resource allocation 0) and the allocation type based on resource block (resource block, RB) (also known as resource allocation 1, resource allocation 1). Each RB includes 12 resource elements (resource element, RE) in the frequency domain, that is, 12 subcarriers. Each RBG contains one or more RBs, and the number of RBs contained in each RBG is also called the size of the RBG. In this application, the size of each RBG can be related to the bandwidth part (Bandwidth Part, BWP). For example, when the number of RBs contained in the bandwidth part BWP is different, the number of RBs contained in each RBG is also different. Optionally, the size of each RBG may be unrelated to the BWP, and the size of each RBG may be indicated by high-level signaling.

[0067] 5. Sub-band

[0068] A subband includes one or more RBs in the frequency domain, or a subband may include one or more RBGs in the frequency domain. Since each RBG also contains multiple RBs, the size of the subband may be the same as or different from the size of the RBG. For example, assuming that a bandwidth part BWP includes 10 RBs, two consecutive RBs are divided into subbands, which can be divided into 5 subbands. Optionally, the subbands can be divided based on the scheduling bandwidth, and the scheduling bandwidth is less than or equal to the size of the bandwidth part BWP. The scheduling bandwidth is the bandwidth corresponding to the actual frequency domain resources occupied by the terminal device to send PUSCH at a certain moment (such as a certain time slot). A subband in an embodiment of the present invention can be an RBG occupied by PUSCH, or it can be an RB occupied by PUSCH.

[0069] 6. Frequency-Selective Gain and Beamforming Gain

[0070] Frequency-selective gain refers to the network equipment calculating the priority of each subband based on the Channel Quality Indicator (CQI) or signal-to-interference-and-noise ratio of each subband, and scheduling each terminal device on each subband according to the subband scheduling priority, so that each terminal device transmits signals on the subband with the best channel quality.

[0071] For beamforming gain, the terminal device weights the uplink signal to form a narrow beam aimed at the network device, or it can be understood as a directional beam, which directs the energy to the target network device, which helps to improve the received signal strength.

[0072] 7. Channel Reciprocity

[0073] Generally, when a terminal device can directly derive uplink channel information from downlink channel information, or a network device can directly derive downlink channel information from uplink channel information, it can be considered that the communication system has channel reciprocity characteristics.

[0074] 8. Codebook

[0075] A codebook consists of multiple precoding matrices. Taking a terminal device with two transmit antenna ports as an example, Tables 1 and 2 provide codebook examples for single- and dual-stream transmission. Each precoding matrix in the codebook corresponds to an index value, also known as a TPMI index.

[0076] Table 1

[0077]

[0078] Table 1 is an example of a codebook when the terminal device has 2 transmitting antenna ports and a rank of 1. As shown in Table 1, there are six precoding matrices, and the corresponding TPMI index values ​​are 0 to 5 respectively.

[0079] Table 2

[0080]

[0081] Table 2 shows the codebook when the terminal transmit antenna port is 2 and the rank is 2. There are three precoding matrices in total, and the corresponding TPMI index values ​​are 0 to 2 respectively.

[0082] In Tables 1 and 2, W is a precoding matrix or vector. Once the precoding matrix is ​​determined, the terminal device maps the PUSCH data to each antenna port using the precoding matrix. For example, the terminal device can map the PUSCH data to the antenna port using the process of formula (1-1):

[0083]

[0084] y (υ-1) (i) is the data before precoding, v is the layer index, is the data after precoding, that is, the corresponding antenna port p ρ-1 For single-layer transmission of two antennas, that is, p ρ-1 is 2, and v is 1. If single-antenna transmission is used, W defaults to 1, which means no precoding is performed.

[0085] By measuring the SRS, the network device can obtain the channel state information of the uplink channel and select a precoding matrix. For example, it can be the precoding matrix that is most suitable for the current uplink channel, and the TPMI of the precoding matrix is ​​sent to the terminal device. In an example of selecting a precoding matrix, the network device can select an optimal precoding matrix for uplink PUSCH transmission based on the capacity maximization criterion. After the network device determines the TPMI, it needs to send the TPMI to the terminal device before the terminal device sends the uplink data to inform the terminal device which precoding matrix to use to send the uplink data. For example, taking the codebook of one layer of transmission as an example, assuming that the terminal device is k, and in the channel from the terminal device to the network device, the power on the mth frequency domain resource is p k,m , the signal to interference plus noise ratio (SINR) on the mth frequency domain resource is γ k,m The channel on the mth frequency domain resource of terminal device k is H k,m Matrix. SINR is defined as:

[0086]

[0087] where g k,m is the weight coefficient on the network device receiving antenna, w k is the precoding matrix of terminal device k. For example, using the matched filtering method to solve, we can get g k,m =(H k,m w k ) H , I k,m is the interference covariance matrix between cells, σ 2 is the noise power. An optional selection criterion is to select the precoding matrix by maximizing the capacity:

[0088]

[0089] Where Φ is the set of precoding matrices. When the same precoding matrix is ​​used on each frequency domain resource of the terminal device, w k It has nothing to do with the frequency domain resource index.

[0090] In embodiments of the present invention, in a codebook-based transmission mode, the network device and the terminal device can use the same codebook. The precoding matrices in different codebooks may also be different. In addition to using existing candidate codebooks, embodiments of the present invention can also use new codebooks. For example, codebooks generated based on structured antenna grouping or codebooks generated based on the Discrete Fourier Transform (DFT) can be used.

[0091] In one embodiment, a codebook generated based on structured antenna grouping is used. This embodiment can divide the codebook into precoding matrix subsets based on phase. Furthermore, in the codebook generated based on structured antenna grouping, since each precoding matrix corresponds to one or more phase values, the embodiment of the present invention divides the precoding matrices included in the codebook into subsets based on the phase corresponding to the precoding matrix, thereby forming multiple precoding matrix subsets. For example, for a codebook with 8 antenna ports, if A1 is a precoding matrix with 8 antenna ports and a rank of 1, the codebook is generated as follows:

[0092]

[0093] Among them, θ, ε, δ, φ are different phases. Since each phase can have multiple values, the phase can also be understood as a phase variable. B, D, E, F∈{exp(jθ)}, p is the number of rows in the A1 matrix, q is the number of columns, and N1, N1, N3, and N4 are quantization factors. The quantization factors control the accuracy of the codebook. Larger quantization factors allow for more optional phases and higher precision in the precoding matrix within the codebook. The quantization factors can be configured via Radio Resource Control (RRC) signaling or the Media Access Control Element (MAC CE). For non-8-antenna ports, such as 2 or 4 antenna ports, this method still applies; the difference is that the phases may vary.

[0094] For the codebook generated based on DFT, taking the case of 8 antenna ports as an example, the structure of the precoding matrix of this method can be expressed as:

[0095]

[0096] where v t,m The precoding matrix is ​​formed in the same polarization direction and is composed of DFT matrices. θ is the phase offset in different polarization directions. This method is also applicable to codebook generation when the number of antenna ports is not 8, such as when the number of antenna ports is 2, 4, or 16.

[0097] Since the precoding matrix in the codebook is divided into multiple precoding matrix subsets, in this case, the codebook can also be understood as a codebook set.

[0098] The choice of precoding matrix affects the demodulation performance of the PUSCH. An inappropriate precoding matrix can lead to a decrease in PUSCH demodulation performance. Therefore, a larger codebook size means more precoding matrices in the codebook and more precoding matrices to choose from. This results in higher precision for the precoding matrix, but also increases the signaling overhead for the TPMI indication information.

[0099] For example, if the codebook includes 256 precoding matrices, 8 bits are required to indicate the precoding matrix index. Based on this situation, if the indication is based on subband, assuming there are M subbands and each subband can select a precoding matrix from the codebook, 8*M bits are required to indicate a precoding matrix index corresponding to each subband. Assuming M=40, 320 bits are required. If these 320 bits are directly carried by DCI, on the one hand, the DCI occupies more control channel resources, causing control channel congestion and reduced reliability. On the other hand, the number of bits carried by the DCI exceeds the size of the DCI used for downlink scheduling, which increases the number of blind detections by terminal devices.

[0100] Currently, only bandwidth-based precoding matrices are considered when designing precoding matrices. This approach uses the same precoding matrix for all scheduled resources allocated to a terminal device. This approach is suitable for situations where the frequency domain channel is relatively flat and has minimal channel variation. However, when the channel fluctuates significantly in the frequency domain, the bandwidth-based precoding matrix may not be able to match the channel variation, hindering the achievement of frequency-selective gain and beamforming gain. Furthermore, when pairing multiple terminal devices, since different terminal devices can be paired on different frequency domain resource blocks, using a bandwidth-based precoding matrix is ​​not conducive to suppressing interference between paired terminal devices.

[0101] In one embodiment of the present application, a communication method is provided for enabling uplink subband-level precoding matrix while reducing signaling overhead. Figure 2 , which is the flow chart of this method. In the following introduction, this method is applied to Figure 1 Take the network architecture diagram shown in the figure as an example.

[0102] For the sake of convenience, the following text takes the method executed by a network device and a terminal device as an example. Figure 1 The network architecture shown in the figure is taken as an example. Therefore, the network devices described below are, for example, Figure 1 The access network device in the network architecture shown in the figure, the terminal device described below can be Figure 1 Terminal devices in the network architecture shown.

[0103] refer to Figure 2 , is a flow chart of a communication method provided in this application. The method mainly includes S21 to S25.

[0104] S21: The terminal device sends an SRS to the network device. Correspondingly, the network device receives the SRS sent by the terminal device.

[0105] Specifically, the terminal device sends an SRS to the network device on the SRS resources configured by the network device. Correspondingly, the network device receives the SRS on the SRS resources configured by the network device, measures the uplink channel, and obtains channel state information.

[0106] S22: The network device determines N precoding matrix subsets.

[0107] Specifically, the network device determines N precoding matrix subsets based on the state information of the uplink channel obtained by SRS measurement and the scheduling bandwidth. The N precoding matrix subsets are one or more of the multiple precoding matrix subsets divided by the first codebook. Among the N precoding matrix subsets, at least one precoding matrix subset includes at least two precoding matrices. The N precoding matrix subsets determined by the network device can be N different precoding matrix subsets, or can include two or more identical precoding matrix subsets. For example, the network device determines 5 precoding matrix subsets, of which two precoding matrix subsets are the same precoding matrix subset. This is because the scheduling bandwidth can include multiple subbands. When determining the N precoding matrix subsets, the network device considers the channel state information on each subband and determines the precoding matrix subset based on each subband. At this time, there may be two or more subbands in the scheduling bandwidth that are applicable to the same precoding matrix subset.

[0108] The first codebook can be one of the existing candidate codebooks, a codebook generated based on structured antenna grouping, a codebook generated based on a DFT transform, or a codebook generated by some other method. Since the first codebook contains multiple precoding matrices, it can be divided into multiple precoding matrix subsets, each of which contains several precoding matrices. Of course, one or more precoding matrix subsets may also contain only one precoding matrix. When N is greater than 1, the multiple precoding matrices in the first codebook are divided into different precoding matrix subsets. The N precoding matrix subsets can include one or more precoding matrix subsets from the multiple precoding matrix subsets divided by the first codebook, or they can include all precoding matrix subsets from the multiple precoding matrix subsets divided by the first codebook. In this case, the N precoding matrix subsets can be understood as the first codebook itself. Since each precoding matrix subset also contains one or more precoding matrices, if each precoding matrix subset is considered a codebook, the first codebook can be understood as a codebook set.

[0109] In one optional embodiment, the first codebook includes at least one first codebook parameter. Among the multiple precoding matrix subsets divided by the first codebook, at least two different precoding matrix subsets correspond to different values ​​of the first codebook parameter, and the codebook parameter includes a phase. Optionally, the multiple precoding matrices in the first codebook are divided into the multiple precoding matrix subsets by phase. The phase may be a phase offset between antennas or antenna ports. Since each phase can correspond to different values, the phase can also be understood as a phase variable. For example, when the first codebook is generated based on structured antenna grouping, the codebook generated based on structured antenna grouping may have multiple phase variables. A precoding matrix subset can be constructed by fixing the values ​​of one or more phases and iterating over the values ​​of the remaining one or more phases. The value of each phase is determined based on a quantization factor, which is the maximum number of selectable values ​​for each phase. The quantization factor may be a predefined value or indicated by indication information. The indication information indicating the quantization factor may be carried in RRC signaling, in a MAC CE, or in both RRC signaling and MAC CE. Based on this division method, the precoding matrix in the first codebook can be divided into multiple precoding matrix subsets. After the division of the precoding matrix subsets is determined, in order to indicate different subsets, each subset needs to be numbered. The number of the subset can also be understood as the index of each precoding matrix subset. Different precoding matrix subsets can be indicated by different state values ​​of one or more bits of an indication field, and each state value represents a precoding matrix subset. For example, if the codebook generated based on the structured antenna grouping has 4 phases, namely θ, ε, δ, φ, the values ​​of θ, ε, and δ are fixed, and by traversing the possible values ​​of φ To construct a precoding matrix subset, each possible value of φ corresponds to a precoding matrix. Furthermore, the quantization factors of phases θ, ε, δ, and φ are N1, N1, N3, and N4, respectively. This means that θ, ε, δ, and φ can take N1, N1, N3, and N4 different values, respectively. Table 3 shows one way to partition the first codebook into multiple precoding matrix subsets.

[0110] Table 3

[0111]

[0112] In Table 3, there are four phase variables θ, ε, δ, and φ, which are the first to fourth phases, respectively. The quantization factors N1, N1, N3, and N4 corresponding to each phase variable all have a value of 4, corresponding to 64 precoding matrix subsets. For each subset, three phases are fixed values, and the different values ​​of the remaining phase correspond to the multiple precoding matrices in the subset. For example, for subset number 1, the first, second, and third phases are all fixed values, and the N4 values ​​of the fourth phase correspond to the N4 precoding matrices in the precoding matrix subset numbered 1. Optionally, for the 64 precoding matrix subsets, different precoding matrix subsets can be indicated by different state values ​​of a 6-bit indication field in the indication information.

[0113] When generating the codebook, to reduce overhead, two phases may be equal. For example, in the case of the four phase variables described above, if two phase variables are equal, this is equivalent to having only three phases, or it can be understood that only three phases are variable. In other words, only the phase values ​​of these three phases are required to determine a precoding matrix subset. For example, there are four phases θ, ε, δ, and φ, representing the first to fourth phases, respectively. For example, if the second and third phases are the same, that is, ε and δ are the same, then only the values ​​of two phases need to be fixed, and the values ​​of the remaining phase can be traversed to construct a precoding matrix subset. Table 4 shows an example of how the first codebook is divided into multiple precoding matrix subsets when there are four phases and two phases are equal.

[0114] Table 4

[0115]

[0116] As shown in Table 4, the values ​​of N1, N2, N3, and N4 are all 4. There are three variable phases, θ, ε, and δ, which are the first, second, and fourth phases, respectively. This can be understood as the first and third phases being the same, or the second and third phases being the same. For the three variable phases, only the values ​​of two of the phase variables need to be fixed, and the values ​​of the remaining phase can be iterated over to determine the precoding matrix in a precoding matrix subset. For example, in subset number 1, the first and second phases are fixed, and the four different values ​​of the fourth phase correspond to the four precoding matrices in this precoding matrix subset. With three phases and a quantization factor of 4 for each phase, there are a total of 16 precoding matrix subsets. In this case, different state values ​​of the 4-bit indicator field can be used to indicate different precoding matrix subsets.

[0117] For example, if only one phase is variable, the precoding matrix subset corresponding to the one phase can be expressed as shown in the following Table 5:

[0118] Table 5

[0119]

[0120] In Table 5, θ is the phase mentioned above. A precoding matrix subset can be constructed by traversing different values ​​of θ.

[0121] For example, if there are two variable phases, a precoding matrix subset can be constructed by fixing the value of one phase and traversing the value of the other phase. Table 6 shows a possible example:

[0122] Table 6

[0123]

[0124] In Table 6, θ and ε are the first phase and the second phase respectively. The value of the first phase θ is fixed to θ x , a precoding matrix subset can be constructed by traversing different values ​​of the second phase ε.

[0125] The above description of the phase and quantization factor is merely exemplary. The phase value and the size of the quantization factor can also take other forms, which are not limited in this application. At the same time, in the above example, a precoding matrix subset is constructed by traversing the value of one phase and fixing the value of the remaining phase. In actual applications, a precoding matrix subset can also be constructed by traversing two or more phase values ​​and fixing the value of the remaining phase. This application does not limit this.

[0126] In another optional manner, the first codebook includes L precoding matrices, each of the L precoding matrices corresponds to an index value of a precoding matrix, the L precoding matrices are divided into K precoding matrix subsets, each precoding matrix subset includes one or more precoding matrices, and for each precoding matrix subset, the index value of the precoding matrix included therein satisfies The values ​​of are the same, or the index values ​​of the precoding matrices contained therein satisfy the same values ​​of mod(j,K), where j is the index of the precoding matrix, is the floor function, is a ceiling function. For the convenience of description, the following relation 1 is used to represent the index of the precoding matrix in each precoding matrix subset that satisfies The values ​​of are the same, and the relationship 2 is used to represent that the index of the precoding matrix in each precoding matrix subset satisfies the same value of mod(j,K).

[0127] Example 1: When L is equal to 28 and K is equal to 4, the first codebook contains 28 precoding matrices, and the index values ​​of the precoding matrices corresponding to the 28 precoding matrices are 0 to 27, respectively, and are divided into 4 precoding matrix subsets. When the index values ​​of the precoding matrices in each precoding matrix subset satisfy Relationship Formula 1, optionally, the precoding matrices with index values ​​0 to 6, index values ​​7 to 13, index values ​​14 to 20, and index values ​​21 to 27 belong to the first to fourth precoding matrix subsets, respectively: for the first precoding matrix subset, the index values ​​of the precoding matrices contained therein are substituted into Relationship Formula 1 to obtain the values ​​of 0; for the second precoding matrix subset, the index values ​​of the precoding matrices contained therein are substituted into Relationship Formula 1 to obtain the values ​​of 1; for the third precoding matrix subset, the index values ​​of the precoding matrices contained therein are substituted into Relationship Formula 1 to obtain the values ​​of 2; for the fourth precoding matrix subset, the index values ​​of the precoding matrices contained therein are substituted into Relationship Formula 1 to obtain the values ​​of 3.

[0128] In Example 2, when L is 28 and K is 4, the first codebook contains 28 precoding matrices. The precoding matrix index values ​​corresponding to these 28 precoding matrices range from 0 to 27, and the precoding matrices are divided into four precoding matrix subsets. When the precoding matrix index values ​​in each precoding matrix subset satisfy the same value when substituted into Equation 2, it can be understood that several precoding matrices with equally spaced index values ​​constitute a precoding matrix subset. Precoding matrices with index values ​​of 0, 4, 8, 12, 16, 20, and 24 belong to the same precoding matrix subset, or are referred to as the first precoding matrix subset; precoding matrices with index values ​​of 1, 5, 9, 13, 17, 21, and 25 belong to the same precoding matrix subset, or are referred to as the second precoding matrix subset; precoding matrices with index values ​​of 2, 6, 10, 14, 18, 22, and 26 belong to the same precoding matrix subset, or are referred to as the third precoding matrix subset; precoding matrices with index values ​​of 3, 7, 11, 15, 19, 23, and 27 belong to the same precoding matrix subset, or are referred to as the fourth precoding matrix subset.

[0129] Relational equation 1 can also be expressed in another way, that is, when the first codebook is divided into multiple precoding matrix subsets, the division can be performed by multiple precoding matrices with adjacent index values, that is, each precoding matrix subset contains multiple precoding matrices with adjacent index values. Relational equation 2 can also be expressed in another way, that is, when the first codebook is divided into multiple precoding matrix subsets, the multiple precoding matrices can be divided by evenly spaced index values, that is, each precoding matrix subset contains multiple precoding matrices with evenly spaced index values.

[0130] It should be noted that when L is divisible by K, the number of precoding matrices contained in different precoding matrix subsets in the first codebook is the same. When L is not divisible by K, the number of precoding matrices contained in different precoding matrix subsets in the first codebook may be different. Furthermore, there may be a situation where there is only one precoding matrix in a certain precoding matrix subset, which is not limited in this application.

[0131] In another optional manner, if the first codebook is a codebook generated based on DFT, at least two different precoding matrix subsets among the multiple precoding matrix subsets in the first codebook correspond to different column vectors in the DFT transform matrix. That is, the multiple precoding matrices in the first codebook are divided into the multiple precoding matrix subsets by at least one column vector in the DFT transform matrix. Different precoding matrix subsets correspond to different column vectors in the DFT transform matrix.

[0132] For example, for a codebook generated based on DFT, the matrix generated by this method can be expressed as: in, u m It can be understood as a column in the DFT matrix, where N1 and N2 are the number of antenna ports in the horizontal and vertical dimensions, respectively, and O1 and O2 are the oversampling factors in the horizontal and vertical dimensions, respectively. This codebook generation method mainly includes the selected vertical position and horizontal beam, as well as the phase offset in different polarization directions. When constructing the precoding matrix subset, it is necessary to determine v t,m The indices of t and m and the phase θ, where each t value corresponds to a beam in the horizontal direction and each m value corresponds to a beam in the vertical direction.

[0133] For the precoding matrix subset partitioning based on the DFT-generated codebook, an optional precoding matrix subset construction method can be expressed as follows: given a certain t and m, θ is variable. For example, when t and m are 1, θ is Another optional method for constructing precoding matrix subsets can be expressed as follows: group the values ​​of t and m, with each group of t, m, and θ forming a precoding matrix set. For example, group the beams corresponding to indices t, t+O1, m, and m+O2 into one group; group the beams corresponding to indices t+1, t+1+O1, m+1, and m+1+O2 into another group; and so on. The grouping in this example assumes that m>1, t>1, O1>1, and O2>1. The grouping method may differ when the above parameters take other values.

[0134] S23: The network device sends downlink control information to the terminal device, where the downlink control information includes the indexes of the N precoding matrix subsets. Correspondingly, the terminal device receives the downlink control information.

[0135] Specifically, the downlink control information includes the indexes of N precoding matrix subsets. Optionally, the downlink control information may also include resource indication information of a first downlink reference signal, and the first downlink reference signal may be a channel state reference signal CSI-RS. The indexes of the N precoding matrix subsets may all be indexes of different precoding matrix subsets. For example, the downlink control information indicates the indexes of 5 precoding matrix subsets, and the 5 index values ​​are 1, 2, 3, 4, and 5, respectively. The same index of the precoding matrix subset may also exist, that is, the same index value may exist in the indexes of the N precoding matrix subsets. For example, the downlink control information indicates the indexes of 5 precoding matrix subsets, and the index values ​​may be 1, 1, 2, 3, and 4, respectively. That is, in this case, two precoding matrix subsets among the 5 precoding matrix subsets are the same precoding matrix subsets.

[0136] S24: The terminal device determines at least N precoding matrices from the N precoding matrix subsets.

[0137] Specifically, the terminal device receives downlink control information, and determines at least N precoding matrices based on the indexes of the N precoding matrix subsets indicated by the downlink control information. When the downlink control information also includes resource indication information of a first downlink reference signal, the terminal device determines at least N precoding matrices based on the indexes of the N precoding matrix subsets indicated by the downlink control information and the first reference signal on the resource indication information. The resources corresponding to the resource indication information of the first reference signal may be time domain resources, frequency domain resources, or time-frequency resources.

[0138] S25: The terminal device sends an uplink signal based on at least N precoding matrices, where N is a positive integer.

[0139] Specifically, the terminal device determines at least N precoding matrices and transmits an uplink signal based on the at least N precoding matrices. Optionally, the uplink signal is a physical shared uplink channel (PUSCH), which occupies multiple subbands. For multiple subbands, each subband includes at least one RB or RBG, and the bandwidth of each subband is less than the bandwidth portion (BWP). When each subband includes one RBG, the size of each subband is the same as the size of the RBG. In this case, since the number of RBs contained in each RBG is related to the bandwidth portion (BWP), it can also be understood that the size of each subband is related to the bandwidth portion (BWP). When each subband includes multiple RBGs, the number of RBGs contained in each subband can be indicated by indication information. In this case, it can also be understood that the size of each subband is independently configured and is unrelated to the size of the bandwidth portion (WBP). This indication information can be carried in DCI, RRC signaling, MAC CE, or both RRC signaling and MCA CE, and this application does not impose any restrictions on this.

[0140] If the PUSCH occupies M subbands, each subband corresponds to a precoding matrix. The precoding matrices on different subbands may be the same or different. Furthermore, the precoding matrices on different subbands may belong to the same precoding matrix subset or different precoding matrix subsets. That is, M is a positive integer greater than or equal to N.

[0141] In Example 1, the number of precoding matrix subsets indicated by the downlink control information is N, and the N precoding matrix subsets are different. The terminal device transmits PUSCH occupying M subbands, where M equals N. In this case, the precoding matrices corresponding to different subbands belong to different precoding matrix subsets, that is, the M precoding matrix subsets correspond to the M subbands in a one-to-one correspondence. Furthermore, when the precoding matrices in the M precoding matrix subsets are different, the M different precoding matrices determined by the terminal device correspond to the M subbands in a one-to-one correspondence.

[0142] In Example 2, the number of precoding matrix subsets indicated by the downlink control information is N, where the N precoding matrix subsets include a total of n different precoding matrix subsets, and N is greater than n. The terminal device occupies M subbands when sending PUSCH, and M is greater than n. At this time, among the M subbands, there are at least two subbands corresponding to the same precoding matrix subset. Furthermore, the precoding matrices corresponding to the at least two subbands can be the same precoding matrix in the same precoding matrix subset, or different precoding matrices.

[0143] Example three: The number of precoding matrix subsets indicated by the downlink control information is 1, that is, N is equal to 1. The terminal device sends PUSCH and occupies M subbands, where M is greater than N. At this time, the M subbands correspond to one precoding matrix subset. Furthermore, the precoding matrices corresponding to the M subbands may be different, or there may be at least two subbands whose corresponding precoding matrices are the same.

[0144] The correspondence between the above N precoding matrix subsets and multiple subbands is merely exemplary. In this application, for multiple subbands, based on the principle of capacity maximization, each subband can correspond to any precoding matrix in any of the N precoding matrix subsets. The precoding matrices corresponding to different subbands can be the same or different, and the precoding matrices on different subbands can belong to the same precoding matrix subset or different precoding matrix subsets. This avoids the situation where the terminal device can only use one precoding matrix to send uplink signals on M subbands, resulting in the one precoding matrix being unable to match the frequency selection gain reduction and beamforming gain reduction caused by channel changes. At the same time, the network device indicates part of the precoding matrix information to the terminal device, which can reduce the signaling overhead of subband-level precoding, reduce the complexity of terminal device detection, and improve transmission performance.

[0145] In addition, in one embodiment, the downlink control information is further used to indicate the index of at least one precoding matrix, and the precoding matrix corresponding to the at least one precoding matrix index is a precoding matrix that the network device does not expect the terminal device to use, or is understood to be a precoding matrix that the network device expects the terminal device to avoid using. Optionally, the precoding matrix corresponding to the at least one precoding matrix index may be a precoding matrix of an interference channel, and further optionally, the interference channel may be an interference channel of a bandwidth part BWP. For example, the network device indicates the precoding matrix of the interference channel to the terminal device, and the terminal device determines at least N precoding matrices in N precoding matrix subsets based on the downlink control information, taking into account the precoding matrix of the interference channel, and the terminal device selects a precoding matrix with as low a correlation as possible with the precoding matrix of the interference channel in the N precoding matrix subsets, thereby avoiding the influence of the interference channel, so that the terminal device can better transmit uplink signals and improve communication quality.

[0146] It should be noted that the present application uses downlink control information as an example for information indication. In actual applications, the content of the downlink control information indication in the present application can be carried in DCI, and can also be carried in RRC signaling or MAC CE. Alternatively, the content of the downlink control information indication requested itself can also be jointly indicated by RRC signaling and MAC CE. This application does not impose any restrictions on this.

[0147] Figure 3 Schematic diagram of the hardware structure of the network equipment and terminal equipment provided for this application.

[0148] The terminal device 130 includes at least one processor 301 , at least one memory 302 , and at least one transceiver 303 . Optionally, the terminal device 130 may further include an output device 304 and an input device 305 .

[0149] The processor 301, the memory 302 and the transceiver 303 are connected via a bus. The processor 301 may be a general-purpose central processing unit (CPU), a microprocessor, an application-specific integrated circuit (ASIC), or one or more integrated circuits for controlling the execution of the program of the present application. The processor 301 may also include multiple CPUs, and the processor 301 may be a single-core (single-CPU) processor or a multi-core (multi-CPU) processor. The processor here may refer to one or more devices, circuits or processing cores for processing data (such as computer program instructions).

[0150] The memory 302 can be a read-only memory (ROM) or other types of static storage devices that can store static information and instructions, a random access memory (RAM) or other types of dynamic storage devices that can store information and instructions, or an electrically erasable programmable read-only memory (EEPROM), a compact disc read-only memory (CD-ROM) or other optical disc storage, optical disc storage (including compressed optical disc, laser disc, optical disc, digital versatile disc, Blu-ray disc, etc.), a magnetic disk storage medium or other magnetic storage device, or any other medium that can be used to carry or store the desired program code in the form of instructions or data structures and can be accessed by a computer, but is not limited to this. The memory 302 can be independent and connected to the processor 301 via a bus. The memory 302 can also be integrated with the processor 301. Among them, the memory 302 is used to store the application code that executes the solution of the present application, and the execution is controlled by the processor 301. The processor 301 is used to execute the computer program code stored in the memory 302, thereby implementing the collaborative transmission method described in the embodiment of the present application.

[0151] The transceiver 303 may be any transceiver-like device for communicating with other devices or communication networks, such as Ethernet, Radio Access Network (RAN), Wireless Local Area Networks (WLAN), etc. The transceiver 303 includes a transmitter Tx and a receiver Rx.

[0152] Output device 304 communicates with processor 301 and can display information in a variety of ways. For example, output device 304 can be a liquid crystal display (LCD), a light emitting diode (LED) display device, a cathode ray tube (CRT) display device, or a projector. Input device 305 communicates with processor 301 and can receive user input in a variety of ways. For example, input device 305 can be a mouse, keyboard, touch screen device, or sensor device.

[0153] The network device 120 includes at least one processor 201, at least one memory 202, at least one transceiver 203 and at least one network interface 204. The processor 201, the memory 202, the transceiver 203 and the network interface 204 are connected via a bus. Among them, the network interface 204 is used to connect to the core network device through a link (for example, an S1 interface), or to connect to the network interface of other access network devices through a wired or wireless link (for example, an X2 interface) (not shown in the figure), and this embodiment of the present application does not specifically limit this. In addition, the relevant description of the processor 201, the memory 202 and the transceiver 203 can refer to the description of the processor 301, the memory 302 and the transceiver 303 in the terminal device 130, which will not be repeated here.

[0154] Figure 4 FIG2 is a schematic diagram of a possible communication device provided by the present application. The communication device 400 can implement the functions of the network device in the above method embodiment, and thus can also achieve the beneficial effects of the above method embodiment. In the embodiment of the present application, the communication device can be as follows: Figure 1 The access network device 120 shown may also be a module (such as a chip) applied to the access network device. The communication apparatus 400 includes a transceiver unit 401 and a processing unit 402 .

[0155] Specifically, the processing unit 402 is used to determine N precoding matrix subsets, where the N precoding matrix subsets are one or more of the multiple precoding matrix subsets divided by the first codebook, and among the N precoding matrix subsets, there is at least one precoding matrix subset that includes at least two precoding matrices. The transceiver unit 401 is used to send downlink control information to the terminal device, where the downlink control information includes the index of the N precoding matrix subsets. Optionally, the transceiver unit 401 is also used to receive an uplink signal sent by the terminal device, where the uplink signal occupies M subbands, and the downlink control information also includes indication information of the M subbands, where the M subbands correspond to the N precoding matrices. For a specific description, please refer to the description in the above method embodiment.

[0156] Figure 5 The structure diagram of a possible communication device provided in the embodiment of the present application. The communication device 500 can realize the functions of the terminal device in the above method embodiment, and thus can also achieve the beneficial effects of the above method embodiment. In the embodiment of the present application, the communication device can be as follows: Figure 1 The terminal device 110 shown may also be a module (such as a chip) applied to the terminal device. The communication device 500 includes a transceiver module 501 and a processing module 502 .

[0157] Specifically, the transceiver module 501 is configured to receive downlink control information from a network device, the downlink control information including indexes of N precoding matrix subsets, where the N precoding matrix subsets are one or more of the multiple precoding matrix subsets divided by the first codebook, and at least one of the N precoding matrix subsets includes at least two precoding matrices. The processing module 502 is configured to determine at least N precoding matrices from the N precoding matrix subsets. The transceiver module 501 is further configured to send an uplink signal to the network device based on the at least N precoding matrices.

[0158] Optionally, the downlink control information also includes resource indication information indicating a first downlink reference signal, and the terminal device determines at least N precoding matrices in N precoding matrix subsets based on the first downlink reference signal on the resources indicated by the resource indication information.

[0159] The uplink signal is PUSCH, which occupies M subbands. The M subbands correspond to N precoding matrix subsets. In the M subbands, each subband corresponds to a precoding matrix. Different subbands correspond to different precoding matrix subsets. They can correspond to different precoding matrices in the same precoding matrix subset, or they can correspond to the same precoding matrix in the same precoding matrix subset.

[0160] In example 1, M is equal to N, the M subbands correspond one-to-one to N different precoding matrix subsets, and the M subbands correspond one-to-one to N precoding matrices in the N precoding matrix subsets.

[0161] In Example 2, M is greater than N, and M subbands correspond to N different precoding subsets. This means that two or more subbands correspond to the same precoding subset. In this case, the precoding matrices corresponding to the two or more subbands corresponding to the same precoding matrix subset can be the same or different.

[0162] In example three, N is equal to 1, and M subbands correspond one-to-one to M precoding matrices in one precoding subset. The M precoding matrices may be M different precoding matrices, or there may be two or more identical precoding matrices.

[0163] For a more detailed description of the transceiver unit 401, transceiver module 501, processing unit 402, and processing module 502, please refer to the relevant description of the above method embodiment and will not be repeated here. The hardware element of the transceiver unit 401 or transceiver module 501 may be a transceiver, and the hardware element of the processing unit 402 or processing module 502 may be a processor.

[0164] Figure 6This is a schematic diagram of the structure of a possible communication device provided in this application. Communication device 600 includes a processor 601 and an interface circuit 602. Processor 601 and interface circuit 602 can be connected via a bus 603. It is understood that interface circuit 602 can be a transceiver or input / output interface. Optionally, communication device 600 may also include a memory for storing instructions executed by processor 601, storing input data required by processor 601 to execute instructions, or storing data generated by processor 601 after executing instructions.

[0165] When the communication device 600 is used to implement the method in the above method embodiment, the processor 601 is used to execute the functions of the above processing unit 402 or processing module 502, and the interface circuit 602 is used to execute the functions of the above transceiver unit 401 or transceiver module 501.

[0166] When the communication device 600 is a chip used in a terminal device, the terminal device chip implements the functions of the terminal device in the above method embodiments. The terminal device chip receives information from other modules in the terminal device (such as a radio frequency module or antenna), and the information is sent by the network device to the terminal device; or the terminal device chip sends information to other modules in the terminal device (such as a radio frequency module or antenna), and the information is sent by the terminal device to the network device.

[0167] When the communication device 600 is a chip used in a network device, the network device chip implements the network device functions described in the above method embodiments. The network device chip receives information from other modules in the network device (such as a radio frequency module or antenna), which is information sent by the terminal device to the network device; or the network device chip sends information to other modules in the network device (such as a radio frequency module or antenna), which is information sent by the network device to the terminal device.

[0168] It is understood that the processor in the embodiments of the present application may be a central processing unit (CPU), or may be other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field programmable gate arrays (FPGA), or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. The general-purpose processor may be a microprocessor or any conventional processor.

[0169] In an embodiment of the present application, a terminal device or a network device includes a hardware layer, an operating system layer running on the hardware layer, and an application layer running on the operating system layer. The hardware layer includes hardware such as a central processing unit (CPU), a memory management unit (MMU), and memory (also called main memory). The operating system can be any one or more computer operating systems that implement business processing through processes, such as a Linux operating system, a Unix operating system, an Android operating system, an iOS operating system, or a Windows operating system. The application layer includes applications such as browsers, address books, word processing software, and instant messaging software. In addition, the embodiment of the present application does not specifically limit the specific structure of the execution subject of the method provided in the embodiment of the present application. As long as it is possible to communicate according to the method provided in the embodiment of the present application by running a program that records the code of the method provided in the embodiment of the present application, for example, the execution subject of the method provided in the embodiment of the present application can be a terminal device or a network device, or a functional module in a terminal device or a network device that can call a program and execute the program.

[0170] In addition, various aspects or features of the present application can be implemented as methods, devices or products using standard programming and / or engineering techniques. The term "product" as used in this application covers computer programs that can be accessed from any computer-readable device, carrier or medium. For example, computer-readable media may include, but are not limited to: magnetic storage devices (e.g., hard disks, floppy disks or tapes, etc.), optical disks (e.g., compact discs (CDs), digital versatile discs (DVDs), etc.), smart cards and flash memory devices (e.g., erasable programmable read-only memories (EPROMs), cards, sticks or key drives, etc.). In addition, the various storage media described herein may represent one or more devices and / or other machine-readable media for storing information. The term "machine-readable medium" may include, but is not limited to, wireless channels and various other media capable of storing, containing and / or carrying instructions and / or data.

[0171] It should be noted that memory of the systems and methods described herein is intended to comprise, but not be limited to, these and any other suitable types of memory.

[0172] The present application also provides a computer program product, which includes: computer program code, which, when executed on a computer, enables the computer to execute the method executed by the terminal device or network device in any of the aforementioned method embodiments.

[0173] The present application also provides a computer-readable storage medium storing a program code. When the program code runs on a computer, the computer executes the method executed by the network device or terminal device in the aforementioned method embodiment.

[0174] The present application also provides a system, which includes at least one terminal device and at least one network device.

[0175] In the above embodiments, all or part of the embodiments may be implemented by software, hardware, firmware, or any combination thereof. When implemented using software, all or part of the embodiments may be implemented in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of the present application are generated. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions may be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions may be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via a wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) method. The computer-readable storage medium may be any available medium that a computer can access or a data storage device such as a server or data center that includes one or more available media integrated therein. The available medium may be a magnetic medium (eg, a floppy disk, a hard disk, a magnetic tape), an optical medium (eg, a high-density digital video disc (DVD)), or a semiconductor medium (eg, a solid state disc (SSD)).

[0176] As used in this specification, the terms "component," "module," "system," and the like are used to refer to computer-related entities, hardware, firmware, a combination of hardware and software, software, or software in execution. For example, a component can be, but is not limited to, a process running on a processor, a processor, an object, an executable file, an execution thread, a program, or a computer. By way of illustration, both applications running on a computing device and a computing device can be components. One or more components can reside in a process or execution thread, and a component can be located on a single computer or distributed between two or more computers. In addition, these components can be executed from various computer-readable media having various data structures stored thereon. Components can communicate, for example, through local or remote processes based on signals having one or more data packets (e.g., data from two components interacting with another component on a local system, a distributed system, or a network, such as the Internet interacting with other systems via signals).

[0177] It should be understood that references to "embodiments" throughout this specification mean that a particular feature, structure, or characteristic associated with the embodiment is included in at least one embodiment of the present application. Therefore, various embodiments throughout this specification do not necessarily refer to the same embodiment. Furthermore, these particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

[0178] It should be understood that in the embodiments of the present application, the numbers "first", "second"... are only for distinguishing different objects, such as to distinguish different network devices, and do not constitute a limitation on the scope of the embodiments of the present application. The embodiments of the present application are not limited to this.

[0179] It should also be understood that in this application, "when", "if" and "if" all mean that the network element will make corresponding processing under certain objective circumstances, which is not a time limit, and does not require the network element to make judgment actions when implementing it, nor does it mean that there are other limitations.

[0180] It should also be understood that, in the present application, “at least one” means one or more, and “more than one” means two or more.

[0181] It should also be understood that in each embodiment of the present application, "A corresponds to B" means that B is associated with A, and B can be determined based on A. However, it should also be understood that determining B based on A does not mean determining B based solely on A, and B can also be determined based on A and / or other information.

[0182] It should also be understood that the term "and / or" as used herein simply describes a relationship between associated objects, indicating that three possible relationships exist. For example, "A and / or B" can represent: A exists alone, A and B exist simultaneously, or B exists alone. Furthermore, the character " / " as used herein generally indicates that the associated objects are in an "or" relationship.

[0183] In this application, expressions similar to “the item includes one or more of the following: A, B, and C” generally mean, unless otherwise specified, that the item can be any one of the following: A; B; C; A and B; A and C; B and C; A, B and C; A and A; A, A and A; A, A and B; A, A and C, A, B and B; A, C and C; B and B, B, B and B, B, B and C, C and C; C, C and C, and other combinations of A, B and C. The above examples use A, B, and C as an example to illustrate the optional items of the item. When the expression is “the item includes at least one of the following: A, B, …, and X”, that is, when the expression contains more elements, the items applicable to the item can also be obtained according to the above rules.

[0184] It is understood that in the embodiments of the present application, the terminal device and / or the network device may perform some or all of the steps in the embodiments of the present application. These steps or operations are merely examples, and the embodiments of the present application may also perform other operations or variations of various operations. In addition, the various steps may be performed in a different order than those presented in the embodiments of the present application, and it is possible that not all of the operations in the embodiments of the present application need to be performed.

[0185] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0186] Those skilled in the art will clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0187] In the several embodiments provided in this application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are merely schematic. For example, the division of the units is merely a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0188] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0189] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0190] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory ROM, a random access memory RAM, a magnetic disk, or an optical disk.

[0191] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A communication method, characterized in that: The method comprises: receiving downlink control information from a network device, the downlink control information including indexes of N precoding matrix subsets, the N precoding matrix subsets being one or more of a plurality of precoding matrix subsets divided by a first codebook, at least one of the N precoding matrix subsets including at least two precoding matrices; Determining at least N precoding matrices from the N precoding matrix subsets; Sending an uplink signal based on the at least N precoding matrices, where N is a positive integer; At least two different precoding matrix subsets in the multiple precoding matrix subsets correspond to different values ​​of a first codebook parameter, where the first codebook parameter includes a phase, and the phase is adjusted by a quantization factor, which is configured by radio resource control signaling.

2. The method according to claim 1, wherein The determining of at least N precoding matrices from the N precoding matrices includes: determining at least N precoding matrices from the N precoding matrix subsets based on a first downlink reference signal on a resource indicated by the resource indication information.

3. The method according to claim 1, wherein The uplink signal is a physical uplink shared channel (PUSCH), the PUSCH occupies N subbands, the downlink control information further includes indication information of the N subbands, the at least N precoding matrices are N, the N precoding matrix subsets correspond to the N subbands in a one-to-one correspondence, and the N precoding matrices correspond to the N subbands in a one-to-one correspondence; The sending of uplink signals based on the N precoding matrices includes: sending the PUSCH on the N subbands based on the N precoding matrices.

4. The method according to claim 1, wherein The uplink signal is a physical uplink shared channel PUSCH, the N precoding matrix subsets constitute one precoding matrix subset, and the PUSCH occupies M subbands; Determining at least N precoding matrices in the N precoding matrix subsets includes: determining M precoding matrices in the one precoding matrix subset, where the M precoding matrices correspond one-to-one to the M subbands; The sending of uplink signals based on the N precoding matrices includes: sending the PUSCH on the M subbands based on the M precoding matrices.

5. The method according to any one of claims 1 to 4, characterized in that The number of the plurality of precoding matrix subsets is K, the first codebook includes L precoding matrices, and the index of the precoding matrix included in each precoding matrix subset in the plurality of precoding matrix subsets satisfies: The values ​​of are the same, or the values ​​of mod(j,K) are the same, where j is the index of each precoding matrix in the first codebook, is the floor function, is the ceiling function.

6. The method according to any one of claims 1 to 4, characterized in that The first codebook is generated based on a discrete Fourier transform matrix, and at least two different precoding matrix subsets among the multiple precoding matrix subsets correspond to different column vectors in the discrete Fourier transform matrix.

7. The method according to any one of claims 1 to 4, characterized in that The downlink control information further includes: an index of at least one precoding matrix, where the at least one precoding matrix is ​​a precoding matrix that is not expected to be used by the terminal device.

8. A communication method, characterized in that: The method comprises: Determining N precoding matrix subsets; Sending downlink control information to a terminal device, where the downlink control information includes indexes of N precoding matrix subsets, where the N precoding matrix subsets are one or more of a plurality of precoding matrix subsets divided by a first codebook, and at least one of the N precoding matrix subsets includes at least two precoding matrices; At least two different precoding matrix subsets in the multiple precoding matrix subsets correspond to different values ​​of a first codebook parameter, where the first codebook parameter includes a phase, and the phase is adjusted by a quantization factor, which is configured by radio resource control signaling.

9. The method according to claim 8, wherein The downlink control information further includes: resource indication information for indicating a first downlink reference signal, where the first downlink reference signal is used by the terminal device to determine at least N precoding matrices in the N precoding matrix subsets.

10. The method according to claim 9, wherein The at least N precoding matrices correspond to M subbands, where M is greater than or equal to N. The method further includes: receiving an uplink signal on the M subbands, where the uplink signal is a physical uplink shared channel PUSCH.

11. The method according to claim 9, wherein The at least N precoding matrices belong to M different precoding matrix subsets, or the at least N precoding matrices belong to the same precoding matrix subset.

12. The method according to any one of claims 8 to 11, characterized in that The number of the plurality of precoding matrix subsets is K, the first codebook includes L precoding matrices, and each of the plurality of precoding matrix subsets includes a precoding matrix that satisfies: The values ​​of are the same, or the values ​​of mod(j,K) are the same, where j is the index of each precoding matrix in the first codebook, is the floor function, is the ceiling function.

13. The method according to any one of claims 8 to 11, wherein: The first codebook is generated based on a discrete Fourier transform matrix, and at least two different precoding matrix subsets among the multiple precoding matrix subsets correspond to different column vectors in the discrete Fourier transform matrix.

14. The method according to any one of claims 8 to 11, wherein: The downlink control information further includes: an index of at least one precoding matrix, where the at least one precoding matrix is ​​a precoding matrix that is not expected to be used by the terminal device.

15. A communication device, comprising: a receiving unit, configured to receive downlink control information from a network device, the downlink control information including indexes of N precoding matrix subsets, the N precoding matrix subsets being one or more of a plurality of precoding matrix subsets divided by a first codebook, at least one of the N precoding matrix subsets including at least two precoding matrices; a processing unit, configured to determine at least N precoding matrices from the N precoding matrix subsets; a sending unit, configured to send an uplink signal based on the at least N precoding matrices, where N is a positive integer; At least two different precoding matrix subsets in the multiple precoding matrix subsets correspond to different values ​​of a first codebook parameter, where the first codebook parameter includes a phase, and the phase is adjusted by a quantization factor, which is configured by radio resource control signaling.

16. The communication device according to claim 15, wherein: The downlink control information further includes: resource indication information for indicating a first downlink reference signal; The determining of at least N precoding matrices from the N precoding matrices includes: determining at least N precoding matrices from the N precoding matrix subsets based on the first downlink reference signal on the resource indicated by the resource indication information.

17. The communication device according to claim 15, wherein: The uplink signal is a physical uplink shared channel (PUSCH), the PUSCH occupies N subbands, the downlink control information further includes indication information of the N subbands, the N precoding matrix subsets correspond to the N subbands in a one-to-one correspondence, and the N precoding matrices correspond to the N subbands in a one-to-one correspondence; The sending of uplink signals based on the N precoding matrices includes: sending the PUSCH on the N subbands based on the N precoding matrices.

18. The communication device according to claim 15, wherein: The uplink signal is a physical uplink shared channel PUSCH, the N precoding matrix subsets constitute one precoding matrix subset, and the PUSCH occupies M subbands; Determining at least N precoding matrices in the N precoding matrix subsets includes: determining M precoding matrices in the one precoding matrix subset, where the M precoding matrices correspond one-to-one to the M subbands; The sending of uplink signals based on the N precoding matrices includes: sending the PUSCH on the M subbands based on the M precoding matrices.

19. The communication device according to any one of claims 15 to 18, wherein: The number of the plurality of precoding matrix subsets is K, the first codebook includes L precoding matrices, and each of the plurality of precoding matrix subsets includes a precoding matrix that satisfies: The values ​​of are the same, or the values ​​of mod(j,K) are the same, where j is the index of each precoding matrix in the first codebook, is the floor function, is the ceiling function.

20. The communication device according to any one of claims 15 to 18, wherein: The first codebook is generated based on a discrete Fourier transform matrix, and at least two different precoding matrix subsets among the multiple precoding matrix subsets correspond to different column vectors in the discrete Fourier transform matrix.

21. The communication device according to any one of claims 15 to 18, wherein: The downlink control information further includes: an index of at least one precoding matrix, where the at least one precoding matrix is ​​a precoding matrix that is not expected to be used by the terminal device.

22. A communication device, characterized in that: The communication device comprises: a processing unit, configured to determine N precoding matrix subsets; a sending unit, configured to send downlink control information to a terminal device, the downlink control information including indexes of N precoding matrix subsets, the N precoding matrix subsets being one or more of a plurality of precoding matrix subsets divided by a first codebook, at least one of the N precoding matrix subsets including at least two precoding matrices; At least two different precoding matrix subsets in the multiple precoding matrix subsets correspond to different values ​​of a first codebook parameter, where the first codebook parameter includes a phase, and the phase is adjusted by a quantization factor, which is configured by radio resource control signaling.

23. The communication device according to claim 22, wherein: The downlink control information further includes: resource indication information for indicating a first downlink reference signal, where the first downlink reference signal is used by the terminal device to determine at least N precoding matrices in the N precoding matrix subsets.

24. The communication device according to claim 23, wherein The at least N precoding matrices correspond one-to-one to at least N subbands. The communication device further includes: a receiving unit, configured to receive an uplink signal on the at least N subbands, where the uplink signal is a physical uplink shared channel PUSCH.

25. The communication device according to claim 23, wherein The at least N precoding matrices belong to M different precoding matrix subsets, or the at least N precoding matrices belong to the same precoding matrix subset.

26. The communication device according to any one of claims 22 to 25, characterized in that: The number of the plurality of precoding matrix subsets is K, the first codebook includes L precoding matrices, and each of the plurality of precoding matrix subsets includes a precoding matrix that satisfies: The values ​​of are the same, or the values ​​of mod(j,K) are the same, where j is the index of each precoding matrix in the first codebook, is the floor function, is the ceiling function.

27. The communication device according to any one of claims 22 to 25, characterized in that: The first codebook is generated based on a discrete Fourier transform matrix, and at least two different precoding matrix subsets among the multiple precoding matrix subsets correspond to different column vectors in the discrete Fourier transform matrix.

28. The communication device according to any one of claims 22 to 25, characterized in that: The downlink control information further includes: an index of at least one precoding matrix, where the at least one precoding matrix is ​​a precoding matrix that is not expected to be used by the terminal device.

29. A communication device, characterized in that: include: At least one processor and an interface circuit, wherein the interface circuit is used to provide input or output of instructions and / or data for the at least one processor, and when the at least one processor executes the above instructions, the device implements the method according to any one of claims 1 to 7 or claims 8 to 14.

30. A computer-readable storage medium, characterized in that The method comprises a program or an instruction, and when the program or the instruction is run on a computer, the method according to any one of claims 1 to 7 or claims 8 to 14 is executed.

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